This investigation was designed to study the possible effects (e.g., toxicity and induced dominant lethals) of orally administered AF- 2 in mice. Initially, several toxicity tests were conducted employing male mice of three inbred strains and using several doses of orally administered AF-2. Subsequent to these tests 150 strain DBA/2J males were randomized into 5 groups of 30 mice each, treated with AF-2 at doses ranging from 0.0 mg/kg to 450 mg/kg of body weight and then tested according to the dominant lethal assay. AF-2 in the strains tested was relatively non-toxic at doses of up to 900 mg/kg of body weight. However, in those tests where the mice were deliberately starved of food and water for 24 hours prior to treatment, significant increases in AF-2 related deaths were noted. Regarding the dominant lethal test, results obtained in this experiment showed no indication of AF-2 induced dominant lethality.